A good recommendation on two fronts. I know some 'federations' are not up to scratch, according to readers, but this federation is actually a non-affiliated campaigning pressure group for the self-employed and does a lot of good lobbying. I wouldn't hesitate to recommend them either.
Others to consider are the Forum of Private Business and the Association of Convenience Stores. The latter, we at C-Store know, has a fine set of pearly white choppers that it is not afraid of using.